[1,3-Dioxo-2-substituted and 2,2-disubstituted- indanyloxy (or thio] alkanoic acids

ABSTRACT

[1,3-Dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]alkanoic acids and their salts, esters and amides are disclosed. The products display a dual pharmaceutical utility in that they exhibit diuretic, saluretic and uricosuric activity. The acid products are prepared by treating a (2,2-di or 2-)substituted-6-hydroxy-(or mercapto)-1,3-indanedione with a haloalkanoic acid or ester thereof and if the ester is employed hydrolyzing the ester.

The invention relates to a new class of chemical compounds which can be described generally as [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]-alkanoic acids and to the non-toxic, pharmacologically acceptable salt, ester and amide derivatives. It is also an object of this invention to describe a method for the preparation of the [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]alkanoic acids. Pharmacological studies show that the instant products are effective diuretic and saluretic agents which can be used in the treatment of conditions associated with electrolyte and fluid retention. The instant products are also useful in the treatment of hypertension. In addition, these compounds are able to maintain the uric acid concentration in the body at pretreatment levels or to even effect a decrease in the uric acid concentration.

When administered in therapeutic dosages, in conventional vehicles, the instant products effectively reduce the amount of sodium and chloride ions in the body, lower dangerous excesses of fluid levels to acceptable levels and, in general, alleviate conditions usually associated with edema. In addition, these compounds overcome a major problem associated with many of the presently available diuretics and saluretics. Many of the presently available diuretics and saluretics have a tendency upon administration to induce hyperuricemia which may precipitate uric acid or sodium urate, or both, in the body which may cause from mild to severe cases of gout. The instant compounds of this invention now provide an effective tool to treat those patients requiring diuretic and saluretic treatment without incurring the risk of inducing gout.

[1,3-Dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]alkanoic acids of the invention include the racemates and pure enantiomers which have the following structural formula: ##SPC1##

Wherein

A is oxygen or sulfur;

R is lower alkyl containing from 1 to 5 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl and the like; cycloalkyl, for example, cycloalkyl containing from 5-6 nuclear carbon atoms such as cyclopentyl, cyclohexyl and the like, aryl such as phenyl and substituted aryl wherein the substituent is lower alkyl or halo;

R¹ is hydrogen, lower alkyl containing from 1 to 5 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl and the like, lower alkenyl containing from 3 to 5 carbon atoms such as allyl, 1-, 2-or 3-butenyl, 1-, 2-, 3- or 4-pentenyl and the like, lower alkynyl containing from 3 to 5 carbon atoms such as propargyl, 1-, 2- or 3-butynyl, 1-, 2-, 3- or 4-pentynyl and the like, phenyl lower alkyl wherein the lower alkyl contains from 1 to 3 carbon atoms such as benzyl, phenethyl, phenylpropyl and the like, phenyl lower alkenyl wherein the lower alkenyl contains from 2-5carbon atoms such as cinnamyl and the like, aryl such as phenyl or substituted aryl such as loweralkylaryl or haloaryl, or

R and R¹ may be joined together with the carbon atoms to which they are attached to form a cycloalkyl radical containing from 3 to 7 nuclear carbon atoms, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like;

X¹ is hydrogen, methyl or halo such as chloro, bromo, fluoro and the like; and

X² is methyl or halo such as chloro, bromo, fluoro and the like or X¹ and X² may be joined to form a hydrocarbylene chain containing from 3 to 4 carbon atoms, for example, trimethylene, tetramethylene, 1,3-butadienylene and the like, and

Y is an alkylene or haloalkylene radical having a maximum of 4 carbon atoms which contain from 1-3 linear carbon atoms between the oxy (or thio) and carboxy group, for example, methylene, ethylidene, propylidene, isopropylidene, ethylene, trimethylene, fluoromethylene and the like, and the non-toxic pharmaceutically acceptable salt, ester and amide derivatives thereof.

The preferred embodments of this invention are the racemates and the pure enantiomers of [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]alkanoic acids having the following structural formula: ##SPC2##

wherein

R³ is lower alkyl containing from 1 to 3 carbon atoms such as methyl, ethyl, n-propyl or isopropyl or cycloalkyl containing 5 or 6 nuclear carbon atoms such as cyclopentyl or cyclohexyl and

R⁴ is hydrogen, lower alkyl containing from 1 to 3 carbon atoms such as methyl, ethyl, n-propyl or isopropyl, phenyl; or

R³ and R⁴ may be joined together with the carbon atom to which they are attached to form a cycloalkyl radical containing from 5 to 6 nuclear carbon atoms such as cyclopentyl, cyclohexyl and the like, and

X³ and X⁴ are the same or different radicals selected from methyl or chloro; and the non-toxic, pharmacologically acceptable salt, ester and amide derivatives.

The foregoing class of compounds exhibits particularly good diuretic and saluretic activity and also either maintains the uric acid concentration in the body at pretreatment levels or even causes a decrease in the uric acic concentration.

A further more preferred embodiment of this invention are the racemates and pure enantiomers of [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]-alkanoic acids having the formula: ##SPC3##

wherein

R⁷ is lower alkyl containing 1 to 3 carbon atoms such as methyl, ethyl, n-propyl or isopropyl;

R⁸ is hydrogen, lower alkyl containing from 1 to 3 carbon atoms such as methyl, ethyl, n-propyl, isopropyl or phenyl; and

X³ and X⁴ are the same or different radicals selected from methyl or chloro; and the non-toxic pharmaceutically acceptable salt and ester derivatives thereof.

The foregoing especially preferred class of compounds also exhibit particularly good diuretic and saluretic activity and also either maintain the uric acid concentration in the body at pretreatment levels or even cause a decrease in the uric acid concentration.

The [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]alkanoic acids and ester (I) wherein Y contains 1 or 3 linear carbon atoms may be prepared by an etherification method which comprises reacting a haloalkanoic acid or ester thereof of the formula: ##STR1## wherein R⁵ is hydrogen or lower alkyl such as methyl, ethyl and the like, and

Z is halo such as bromo, chloro, iodo and the like with a suitable 2-mono or 2,2-disubstituted-6-hydroxy (or mercapto)-1,3-indanedione (II, infra).

The following equation illustrates this reaction: ##SPC4##

wherein

X¹, x², r, r⁵ and Z are as defined above;

R¹ is lower alkyl, lower alkenyl, halo lower alkenyl, lower alkynyl, phenyl lower alkyl, phenyl lower alkenyl or phenyl, wherein these substituents are as defined above under the definition of R¹ ; or

R and R¹ may be joined together with the carbon atom to which they are attached to form a cycloalkyl radical containing from 4 to 7 nuclear carbon atoms; and

Y is an alkylene or haloalkylene radical containing 1 or 3 linear carbon atoms as defined bove.

In general, the reaction is conducted in the presence of a base such as an alkali metal cabonate, hydroxide or alkoxide such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, sodium ethoxide and the like. Any solvent which is inert or substantially inert to the reactants and in which the reagents are reasonably soluble may be employed. Acetone, ethanol and dimethylformamide, for example, have proved to be particularly advantageous solvents. The reaction may be conducted at a temperature in the range of from about 25°C. to the reflux temperature of the particular solvent employed. The reaction with the haloalkanoic acid or ester is generally complete in about 10 to 60 minutes. If the haloalkanoic acid ester is employed, the ester obtained may be hydrolyzed to the free acid by methods well known to those skilled in the art.

Those [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]alkanoic acids (I) wherein the alkylene chain contains 2 linear carbon atoms between the carboxy and oxy (or thio) groups are prepared from their corresponding 2-mono or 2,2-disubstituted-6-hydroxy-(or mercapto)-1,3-indanediones (II) by the reaction of the latter with propiolactone or with an appropriately substituted propiolactone, in the presence of a base such as an aqueous solution of sodium hydroxide, preferably, while heating the solution at reflux temperatures; followed by the acidification of the carboxylate intermediate thus formed to the desired acid. The following equation illustrates the reaction: ##SPC5##

wherein A, R, R¹, R⁵, X¹ and X² are as defined above and M is a cation derived from an alkali metal hydroxide or alkali metal carbonate such as a sodium or potassium cation.

Another process for preparing [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)]alkanoic acids comprises reacting a substituted phenoxyalkanoic acid, a substituted phenylthioalkanoic acid or a lower alkyl ester of the acid with a mono-or di-substituted malonyl chloride in the presence of a Friedel Crafts catalyst such as aluminum chloride and the like. The reaction solvent and the temperature at which the reaction is conducted are not particularly critical aspects of this reaction inasmuch as any solvent which is inert to the starting materials may be employed with good results. In this regard, it has been found that methylene chloride is a particularly suitable solvent. The following equation illustrates this reaction: ##SPC6##

wherein X¹, X², R, R¹, A, Y and R⁵ are as previously defined.

It should be noted that if a lower alkyl ester of a substituted phenoxyalkanoic acid or a substituted phenylthio alkanoic acid is used, the ester obtained (Ic) may be hydrolyzed to the free acid by methods well known to those skilled in the art.

The 2-mono- or 2,2-disubstituted-6 -hydroxy-(or mercapto)-1,3-indanediones (II, infra), which also exhibit diuretic and uricosuric activity, are prepared by treating the correspondingly substituted 2-substituted-6 -lower alkoxy-(or lower alkylthio)-1,3-indanedione with an ether cleaving reagent such as aluminum chloride, pyridine hydrochloride, sodium in liquid ammonia and the like. When aluminum chloride is employed, the solvent may be heptane, carbon disulfide, methylene chloride and the like and when pyridine hydrochloride is employed, it is not necessary to employ a solvent. The following equation illustrates this process: ##SPC7##

wherein A, R, R¹, X¹ and X² are as defined above, and R⁶ is lower alkyl.

Compounds shown as III above can be prepared by several methods. The following equation illustrates one process: ##SPC8##

wherein X¹, X², R, R¹, R⁶ and A are as described above.

Generally to prepare Compound III above, an ether of a 2,3-disubstituted phenol (or thiophenol) Compound IV (known compounds) are reacted with a mono- or di-substituted malonyl chloride in the presence of a Friedel Crafts catalyst such as aluminum chloride and the like. The reaction solvent and the temperature at which the reaction is conducted are not particularly critical aspects of this invention inasmuch as any solvent which is inert to the reactants may be employed with good results. In this regard, methylene chloride has been found to be a particularly good solvent.

Another method for preparing a 2,2-disubstituted-6-lower alkoxy-1,3-indanedione (IIIa, infra) consists of alkylating or arylating a 2-monosubstituted-6-lower alkoxy-1,3-indanedione (V, infra) with an alkylating or arylating agent R² Z wherein

R² is lower alkyl containing from 1 to 5 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl and the like, lower alkenyl containing from 3 to 5 carbon atoms such as allyl, 1-, 2- or 3-butenyl, 1-, 2-, 3- or 4-pentenyl and the like, lower alkynyl containing from 3 to 5 carbon atoms such as propargyl, 1-, 2- or 3-butynyl, 1-, 2-, 3- or 4-pentynyl and the like, phenyl lower alkyl wherein the lower alkyl contains from 1 to 3 carbon atoms such as benzyl, phenethyl, phenylpropyl and the like, phenyl lower alkenyl wherein the lower alkenyl contains from 2 to 5 carbon atoms such as cinnamyl and the like or diaryliodonium, e.g., diphenyliodonium or di(substitutedphenyl)iodonium, e.g., ditolyliodonium or di-(p-chlorophenyl)iodonium, and

R, r⁶, x¹, x² and Z are as defined above.

The following equation illustrates this process: ##SPC9##

In general, the reaction is conducted in the presence of a base such as an alkali metal carbonate, hydroxide or alkoxide such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, sodium ethoxide and the like. Any solvent which is inert or substantially inert to the reactants and in which the reagents are reasonably soluble may be employed. Acetone, ethanol and dimethylformamide, for example, have proved to be particularly advantageous solvents. The reaction may be conducted at a temperature in the range of from about 25°C. to the reflux temperature of the particular solvent employed. The reaction with the alkylating or arylating agent is generally complete in about 10 to 60 minutes.

The 2-monosubstituted-6-lower alkoxy-1,3-indanedione (V, supra) are prepared by reacting a phthalate ester (VI, infra) with a ketone, (RCH₂)₂ C=O in an inert solvent such as benzene, toluene, xylene and the like in the presence of a base such as sodium hydride, potassium tert-butoxide and the like at a temperature of from 50°C. to 150°C. but preferably at the refluxing temperature of the solvent employed. The following equation illustrates this process. ##SPC10##

wherein R, R⁶, X¹ and X² are as defined above.

The phthalic acids (VIa, infra) which are esterified by methods well known to those skilled in the art to give the phthalate esters (VI, supra), are prepared by the oxidation of a 2-substituted-5-lower alkoxy-1-indanone (VII, infra) with an oxidizing agent such as potassium permanganate sodium dichromate or chromic acid and the like in a suitable solvent such as water or acetone and the like. The reaction is conducted at from 25°C. to 100°C. but preferably at the reflux temperature of the solvent employed. The following equation illustrates this process: ##SPC11##

wherein R, R⁶, X¹ and X² are as defined above.

The 2-substituted-5-lower alkoxy-1-indanones (VII, supra) are prepared by alkylating a 2-substituted-5-hydroxy-1-indanone (VIII, infra) with an alkylating agent, R⁶ Z, in the presence of a base such as sodium carbonate, potassium carbonate, sodium hydroxide and the like in the presence of an inert solvent such as ethanol, dimethylformamide, acetone and the like at temperatures of from 25°C. to the reflux temperature of the solvent employed.

The following equation illustrates this process: ##SPC12##

Also included within this invention are the enantiomers which can be prepared by resolution of the diastereomers by fractional crystallization of salts derived from optically active amines followed by regeneration (by oxidification) of the resolved acid. Alternate methods of resolution of diastereomeric acids are known to anyone skilled in the art.

Included within the scope of this invention are the ester and amide derivatives of the instant products which are prepared by conventional methods well known to those skilled in the art. Thus, for example, the ester derivative may be prepared by the reaction of a 2-substituted and [1,3-dioxo-2,2-disubstituted-indanyloxy(or thio)]alkanoic acid of this invention with an alcohol, for example, with a lower alkanol. The amide derivatives may be prepared by converting a 2-substituted and [1,3-dioxo-2,2-disubstituted-indanyloxy(or thio)]alkanoic acid to its corresponding acid chloride by treatment with thionyl chloride followed by treating said acid chloride with ammonia, an appropriate mono-lower alkyl amine, di-lower alkyl amine or a hetero amine, such as piperidine, morpholine and the like, to produce the corresponding amide compound. These and other equivalent methods for the preparation of the ester and amide derivatives of the instant products will be apparent to one having ordinary skill in the art and to the extent that said derivatives are both non-toxic and physiologically acceptable to the body system, said derivatives are the functional equivalent of the corresponding [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)] alkanoic acids.

In addition to the salts, esters and amides being functionally equivalent to the carboxylic products those compounds wherein the carboxylic acid is replaced by a 5-tetrazolyl radical are also functionally equivalent to the carboxylic acids. These tetrazole analogs are prepared as depicted in the following equation: ##SPC13##

wherein A, R, R¹, X¹, X² and Z are as defined above.

The 2-substituted-6-hydroxy-indan-1,3-dione (II) is treated with a haloacetonitrile such as chloroacetonitrile, bromoacetonitrile or iodoacetonitrile in the presence of a base such as potassium carbonate and the like in a suitable solvent such as acetone, dimethylformamide, dimethoxyethane and the like at a temperature in the range of from 25° to 100°C. to afford the corresponding nitrile (IX, supra) which, upon treatment with sodium azide and ammonium chloride in dimethylformamide at a temperature in the range of from 25° to 100°C., affords the 5-(1,3-dioxo-2-substituted-6-indanyloxymethyl)tetrazole (X, supra).

The following examples describe the preparation of specific compounds of this invention and are meant to be illustrative only and not limiting to the scope of this invention.

EXAMPLE 1 (1,3-Dioxo-2,2-diethyl-4,5-dimethyl-6-indanyloxy)-acetic acid

Step A: 2,2-Diethyl-4,5-dimethyl-6-methoxy-indan- 1,3-dione

A stirred mixture of 2,3-dimethylanisole (6.8 g., 0.05 mole) and 2,2-diethylmalonyl chloride (10 g., 0.051 mole) in hexane (75 ml.) is cooled to 0°C. and treated with aluminum chloride (13.5 g., 0.11 mole) in several portions over a 15 minute period. The reaction is heated at reflux for 2 hours, the hexane is distilled at reduced pressure, the product treated with cold 1N-hydrochloric acid, extracted into ether, washed with water, 5% sodium hydroxide, water then dried over magnesium sulfate. Evaporation of the ether at reduced pressure affords 6.3 g. of 2,2-diethyl-4,5-dimethyl-6-methoxy-indan-1,3-dione which melts at 80°-81°C. After recrystallization from petroleum ether.

Elemental analysis for C₁₆ H₂₀ O₃ : Calc.: C, 73.82; H, 7.74; Found: C, 74.16; H, 7.79.

Step B: 2,2-Diethyl-4,5-dimethyl-6-hydroxy-indan-1,3-dione

A mixture of 2,2-diethyl-4,5-dimethyl-6-methoxy-indan-1,3-dione (5.5 g., 0.021 mole) and pyridine hydrochloride (50 g.) is heated at 180°C. for six hours then poured into water (1 l) affording 4.0 g. of 2,2-diethyl-4,5-dimethyl-6-hydroxy-indan-1,3-dione which melts at 141°-142°C. after recrystallization from methanol-water.

Elemental analysis for C₁₅ H₁₈ O₃ : Calc.: C, 73.15; H, 7.37; Found: C, 73.65; H, 7.64.

Step C: (1,3-Dioxo-2,2-diethyl-4,5-dimethyl-6-indanyloxy)acetic acid

A stirred mixture of 2,2-diethyl-4,5-dimethyl-6-hydroxy-indan-1,3-dione (3.5 g., 0.014 mole), ethyl bromoacetate (2.7 g., 0.016 mole) and potassium carbonate (2.2 g., 0.016 mole) in dimethylformamide (20 ml.) is heated at 65°C. for two hours, treated with methanol (40 ml.) and potassium hydroxide (1.1 g., 0.02 mole) refluxed for 1/2 hour then poured into dilute hydrochloric acid (500 ml.) affording 4.2 g. of (1,3-dioxo-2,2-diethyl-4,5-dimethyl-6-indanyloxy-acetic acid which melts at 134° 136°C. after recrystallization from acetic acid-water.

Elemental analysis for C₁₇ H₂₀ O₅ : Calc.: C, 67.09; H, 6.62; Found: C, 67.44; H, 6.66.

EXAMPLE 2 (1,3-Dioxo-2,2-diethyl-4,5-dimethyl-6-indanyloxy)acetic acid

A stirred solution of (2,3-dimethylphenoxy)acetic acid (4.5 g., 0.025 mole) and 2,2-diethylmalonyl chloride (5.0 g., 0.0255 mole) in methylene chloride (200 ml.) is cooled to 0°C. and treated in portions with aluminum chloride (10.7 g., 0.08 mole) during a 15 minute period. The reaction is stirred 18 hours at 25°C. then one hour at reflux, cooled and poured into water (500 ml.) containing hydrochloric acid (25 ml.) Evaporation of the methylene chloride affords 6.1 g. of (1,3-dioxo-2,2-diethyl-4,5-dimethyl-6-indanyloxy)acetic acid which melts at 134°-136°C.

EXAMPLE 3 (1,3-Dioxo-2-ethyl-4,5-dimethyl-6-indanyloxy)acetic acid

A solution of methyl (2,3-dimethylphenoxy)acetate (3.0 g., 0.0155 mole) and 2-ethylmalonyl chloride (2.7 g., 0.016 mole) in methylene chloride (200 ml.) is cooled to 0°C. then treated with aluminum chloride (6.6 g., 0.05 mole) in several portions during a 15 minute period. The reaction is stirred for 2 hours at 0°C., 18 hours at 25°C. then at reflux for six hours, cooled and poured into cold 1 N-hydrochloric acid (500 ml.), the organic layer is washed with water, saturated aqueous sodium chloride, dried over magnesium sulfate, then the solvent evaporated at reduced pressure. The crude methyl ester is hydrolyzed by treatment with potassium hydroxide (0.34 g., 0.005 mole) and methanol (20 ml.) at reflux for 1/2 hour, cooled and acidified with aqueous hydrochloric acid affording (1,3-dioxo-2-ethyl-4,5-dimethyl-6-indanyloxy)acetic acid which melts at 187°-193°C. after recrystallization from acetic acid-water.

Elemental analysis for C₁₅ H₁₆ O₅ : Calc.: C, 65.21; H, 5.84; Found: C, 65.09; H, 5.66.

EXAMPLE 4 (1,3-Dioxo-2-cyclopentyl-2,5-dimethyl-4-chloro-6-indanyloxy)-acetic acid

Step A: 2-Cyclopentyl-2-methylmalonyl chloride

Phosphorous pentachloride (60.4 g., 0.29 mole) is added in portions to 2-cyclopentyl-2-methylmalonic acid (26.6 g., 0.143 mole) causing an exothermic reaction. The clear, hot solution is then heated at 95°C. for three hours and distilled affording 29 g. (91%) of 2-cyclopentyl-2-methylmalonyl chloride which distills at 135°-6°/30 mm.

Step B: 2-Cyclopentyl-2,5-dimethyl-4-chloro-6-methoxy-indan-1,3-dione

2-Cyclopentyl-2,5-dimethyl-4-chloro-6-methoxy-indan-1,3-dione is prepared following substantially the same procedure described in Example 1, Step A using the following substances:2-Methyl-3-chloroanisole 7 g. (0.045 mole)2-Cyclopentyl-2-methylmalonyl chloride 11.2 g. (0.05 mole)Methylene chloride 400 ml.Aluminum chloride 13.5 g. (0.10 mole)

The above procedure gives 9 g. of crude 2-cyclopentyl-2,5-dimethyl-4-chloro-6-methoxy-indan-1,3-dione which is used in the next step without further preparation.

Step C: 2-Cyclopentyl-2,5-dimethyl-4-chloro-6-hydroxy-indan-1,3-dione

2-Cyclopentyl-2,5-dimethyl-4-chloro-6-hydroxy-indan-1,3-dione is prepared following substantially the same procedure described in Example 1, Step B using the following substances:

    2-Cyclopentyl-2,5-dimethyl-4-chloro-                                            6-methoxy-indan-1,3-dione                                                                         2.53 g.                                                                              (0.00825 mole)                                       Pyridine hydrochloride                                                                             20 g.                                                 

The above procedure gives 2,3 g. of 2-cyclopentyl-2,5-dimethyl-4-chloro-6-hydroxy-indan-1,3-dione which after recrystallization from acetic acid-water melts at 221°-2°C. Elemental analysis for C₁₆ H₁₇ ClO₃ : Calc.: C, 65.64; H, 5.85; Found: C, 65.74; H, 5.85.

Step D: (1,3-Dioxo-2-cyclopentyl-2,5-dimethyl-4-chloro-6-indanyloxy)acetic acid

(1,3-Dioxo-2-cyclopentyl-2,5-dimethyl-4-chloro-6-indanyloxy)acetic acid is prepared following substantially the same procedure described in Example 1, Step C using the following substances:

    2-Cyclopentyl-2,5-dimethyl-4-chloro-                                            6-hydroxy-indan-1,3-dione                                                                         2    g. (6.85                                                                               m mole)                                       Ethyl bromoacetate  1.25 g. (7.5 m mole)                                       Potassium carbonate 1.04 g. (7.5 m mole)                                       Dimethylformamide   20   ml.                                                   Methanol            40   ml.                                                   Potassium hydroxide 0.5  g. (9.0 m mole)                                  

The above procedure gives 2.2 g. of (1,3-dioxo-2-cyclopentyl-2,5-dimethyl-4-chloro-6-indanyloxy)acetic acid which after recrystallization from acetic acid-water melts at 178°-80°C.

Elemental analysis for C₁₈ H₁₉ ClO₅ : Calc.: C, 61.63; H, 5.46; Found: C, 61.69; H, 5.75.

EXAMPLE 5 [1',3'-Dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-yloxy]acetic acid

Step A: Cyclopentane-1,1-dicarbonyl chloride

Phosphorous pentachloride (73 g., 0.035 mole) is added in portions to cyclopentane-1,1-dicarboxylic acid (27 g., 0.17 mole) causing an exothermic reaction. The clear hot solution is heated at 95°C. for three hours then distilled affording 23 g. of cyclopentane-1,1-dicarbonyl chloride which distills at 105°-115°C./35 mm.

Step B: Methyl [1',3'-dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-yloxy]-acetate

A stirred solution of methyl (2-methyl-3-chlorophenoxy)acetate (3.7 g., 0.0172 mole) and cyclopentane-1,1-dicarbonyl chloride (3.5 g., 0.018 mole) in methylene chloride (200 ml.) is cooled to 0°C. and treated with aluminum chloride (7.2 g., 0.054 mole) in several portions during a 15 minute period. The reaction is stirred at 25°C. for 18 hours than at reflux for 5 hours, cooled and poured into 1N-hydrochloric acid. Evaporation of the methylene chloride at reduced pressure affords methyl [1',3'-dioxo-4'-chloro-5'-methyl-spiro(cyclopentane-1,2'-indan)-6'-yloxy]acetate which melts at 152°-153.5°C. after recrystallization from ethanol-water.

Elemental analysis for C₁₇ H₁₇ ClO₅ : Calc.: C, 60.63; H, 5.09; Found: C, 60.51; H, 5.24.

Step C: [1',3'-Dioxo-4'-chloro-5'-methylspiro-(cyclopentane-1,2'-indan)-6'-yloxy]-acetic acid

A mixture of methyl [1',3'-dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-yloxy]acetate (3.5 g., 0.0104 mole) potassium hydroxide (0.67 g., 0.012 mole) and methanol (200 ml.) is refluxed for 1/2 hour, diluted with water (800 ml.) and acidified with hydrochloric acid affording 3.1 g. of [1',3'-dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-ylox]acetic acid which melts at 204°-4°C. after recrystallization from acetic acid-water.

Elemental analysis for C₁₆ H₁₅ ClO 5: Calc.: C, 59.54; H, 4.68; Found: C, 59.88; H, 4.74.

EXAMPLE 6 (1,3-Dioxo-2,2-diethyl-4-chloro-5-methyl-6-indanyloxy)acetic acid

Step A: Methyl (1,3-dioxo-4-chloro-2,2-diethyl-5-methyl-6-indanyloxy)acetate

Methyl (1,3-dioxo-2,2-diethyl-4-chloro-5-methyl-6-indanyloxy)acetate is prepared following substantially the same procedure described in Example 5, Step B using the following substances:

    Methyl (2-methyl-3-chlorophenoxy)acetate                                                             5.13                                                                               g. (0.025 mole)                                      2,2-Diethylmalonyl chloride                                                                          5   g. (0.0255 mole)                                     Methylene chloride    200 ml.                                                  Aluminum chloride     10.7                                                                               g. (0.08 mole)                                  

The above procedure gives 8 g. of methyl (1,3-dioxo-2,2-diethyl-4-chloro-5-methyl-6-indanyloxy)acetate which after recrystallization from methanol-water melts at 141° -142.5°C.

Elemental analysis for C₁₇ H₁₉ ClO₅ : Calc.: C, 60.27; H, 5.65; Found: C, 60.22; H, 5.68.

Step B: (1,3-Dioxo-2,2-diethyl-4-chloro-5-methyl-6-indanyloxy)acetic acid

(1,3-Dioxo-2,2-diethyl-4-chloro-5-methyl-6-indanyloxy)acetic acid is prepared following substantially the same procedure described in Example 5, Step C using the following substances:

    Methyl (1,3-dioxo-2,2-diethyl-4-chloro-                                         5-methyl-6-indanyloxy)acetate                                                                       5 g., (0.0148 mole)                                      Potassium hydroxide   0.98 g.,                                                                       (0.0175 mole)                                            Methanol              200 ml.                                             

The above procedure gives 4.4 g. of (1,3-dioxo-2,2-diethyl-4-chloro-5-methyl-6-indanyloxy)acetic acid which after recrystallization from acetic acid-water melts at 167°-8.5°C.

Elemental analysis for C₁₆ H₁₇ ClO₅ : Calc.: C, 59.17; H, 5.28; Found: C, 59.55; H, 5.18.

EXAMPLE 7 (1,3-Dioxo-2-ethyl-2-methyl-4,5-dichloro-6-indanyloxy) acetic acid

Step A: 2-Ethyl-5-methoxy-6,7-dichloro-1-indanone

A stirred mixture of 2-ethyl-5-hydroxy-6,7-dichloro-1-indanone (18.3 g., 0.075 mole), potassium carbonate (23 g.) and methyl iodide (15 ml.) in DMF (100 ml.) is warmed at 55°C. for two hours and poured into water (300 ml.). The 2-ethyl-5-methoxy-6,7-dichloro-1-indanone which separates (18 g.) melts at 146°-147°C. after recrystallization from butyl chloride.

Elemental analysis for C₁₂ H₁₂ Cl₂ O₂ : Calc.: C, 55.62; H, 4.67; Found: C, 55.54; H, 4.55.

Step B: 3,4-Dichloro-5-methoxyphthalic acid

2-Ethyl-5-methoxy-6,7-dichloro-1-indanone (4 g.) is suspended in 200 ml. of water containing 1 of 20% sodium hydroxide. The mixture is heated to boiling and potassium permanganate 18 g. is added portionwise over a 4 hour period in such a manner that each time the purple color disappears an additional portion is added. A few drops of methanol are added to destroy the excess permanganate and the manganese oxide is removed by filtration.

The colorless filtrate is acidified with 6N-hydrochloric acid and evaporated to dryness under reduced pressure. The solid residue is extracted with boiling acetone and the extract is evaporated to dryness. The residue (2.57 g.) is suspended in 6N hydrochloric acid (125 ml) and the mixture is boiled for 10 min., cooled and the 3,4-dichloro-5-methoxyphthalic acid is collected. On heating the product in a capillary m.p. tube, it evolves a gas at ca. 210°C. (formation of the anhydride), resolidifies and melts at 218°-220°C.

Step C: Dimethyl (3,4-dichloro-5-methoxy)phthalate

Methyl iodide (20 g., 0.2 mole) is added dropwise during a two hour period to a stirred mixture of 3,4-dichloro-5-methoxy phthalic acid (17.5 g., 0.07 mole) and potassium carbonate (21 g., 0.15 mole) in dimethylformamide (175 ml.) at a temperature of 55°-60°C. The reaction is heated at 55°-60°C. for four additional hours then poured into water (800 ml.) affording 14.5 g. of dimethyl (3,4-dichloro-5-methoxy)phthalate which melts at 109°-111°C. after recrystallization from ether-hexane.

Elemental analysis for C₁₁ H₁₀ Cl₂ O₅ : Calc.: C, 45.07; H, 3.44; Cl, 24.19; Found: C, 45.14; H, 3.35; Cl, 24.28.

Step D: 2-Ethyl-4,5-dichloro-6-methoxyindan-1,3-dione

to a dispersion of sodium hydride (50% in mineral oil, 0.32 g., 6.6 m moles) in dry toluene (20 ml.) is added dimethyl (3,4-dichloro-5-methoxy)phthalate (1.9 g., 6.5 m moles) and 4-heptanone (0.75 g., 6.6 m mole). The reaction is refluxed for 18 hours, cooled and the sodium salt of the product collected and rinsed with benzene. The solid is then dissolved in water and acidified with dilute hydrochloric acid affording 0.9% of 2-ethyl-4,5-dichloro-6-methoxyindan-1,3-dione melts at 153°-4°C. after recrystallization from methanol-water.

Elemental analysis for C₁₂ H₁₀ Cl₂ O₃ : Calc.: C, 52.77; H, 3.69; Cl, 25.96; Found: C, 52.50; H, 3.61; Cl, 25.94.

Step E: 2-Ethyl-2-methyl-4,5-dichloro-6-methoxyindan-1,3-dione

A stirred solution of 2-ethyl-4,5-dichloro-6-methoxyindan-1,3-dione (1.3 g.) in dimethylformamide (15 ml.) is treated with potassium carbonate (1.26 g.) and methyl iodide. After 15 minutes, the reaction is poured into water (75 ml.) affording 1.3 g. of 2-ethyl-2-methyl-4,5-dichloro-6-methoxyindan-1,3-dione which melts at 157°C. after recrystallization from ethanol.

Elemental analysis for C₁₃ H₁₂ Cl₂ O₃ : Calc.: C, 54.38; H, 4.21; Found: C, 54.68; H, 4.28.

Step F: 2-Ethyl-2-methyl-4,5-dichloro-6-hydroxyindan-1,3-dione

2-Ethyl-2-methyl-4,5-dichloro-6-hydroxyindan-1,3-dione is prepared following substantially the same procedure described in Example 1, Step B using the following substances:

    2-Ethyl-2-methyl-4,5-dichloro-                                                  6-methoxyindan-1,3-dione                                                                               1.1 g.                                                Pyridine hydrochloride   10 g.                                            

The above procedure gives 1.0 g. of 2-ethyl-2-methyl-4,5-dichloro-6-hydroxyindan-1,3-dione which after recrystallization from acetic acid melts at 246°C.

Elemental analysis for C₁₂ H₁₀ Cl₂ O₃ : Calc.: C, 52.77; H, 3.69; Found: C, 52.87; H, 3.73.

Step G: (1,3-Dioxo-2-ethyl-2-methyl-4,5-dichloro-6-indanyloxy)acetic acid

(1,3-Dioxo-2-ethyl-2-methyl-4,5-dichloro-6-indanyloxy)acetic acid is prepared following substantially the same procedure described in Example 1, Step C using the following substances:

    2-Ethyl-2-methyl-4,5-dichloro-                                                  6-hydroxyindan-1,3-dione                                                                             690 mg.                                                 Potassium carbonate    925 mg.                                                 Ethyl bromoacetate     1.12 g.                                                 Dimethylformamide      8 ml.                                                   Water                  8 ml.                                                   10N sodium hydroxide   0.7 ml.                                            

The above procedure gives 780 mg. of (1,3-dioxo-2-ethyl-2-methyl-4,5-dichloro-6-indanyloxy)acetic acid which after recrystallization from nitromethane melts at 214°C.

Elemental analysis for C₁₄ H₁₂ Cl₂ O₅ : Calc.: C, 50.77; H, 3.65; Found: C, 50.62; H, 3.70.

EXAMPLE 8 (1,3-Dioxo-2-ethyl-2-phenyl-4,5-dichloro-6-indanyloxy)acetic acid

Step A: 2-Ethyl-2-phenyl-4,5-dichloro-6-methoxyindan-1,3-dione

Potassium tert-butoxide (8.4 g.) dissolved in tert-butanol (300 ml.) is added to a refluxing solution of 2-ethyl-4,5-dichloro-6-methoxyindan-1,3-dione (1.3 g) in tert-butanol (400 ml.)-benzene (200 ml.) and refluxing is continued for 15 min., then diphenyliodonium chloride (19.0 g.) is added and refluxing is continued for an additional 2 hours. The reaction mixture is cooled to 25°, 300 ml. water added, and the mixture concentrated to dryness in vacuo to give 2-ethyl-2-phenyl-4,5-dichloro-6-methoxyindan-1,3-dione.

Step B: 2-Ethyl-2-phenyl-4,5-dichloro-6-hydroxyindan-1,3-dione

By the process of Example 7, Step F, but substituting for the 2-ethyl-2-methyl-4,5-dichloro-6-methoxyindan-1,3-dione used therein, an equivalent amount of 2-ethyl-2-phenyl-4,5-dichloro-6-methoxyindan-1,3-dione there is obtained 2-ethyl-2-phenyl-4,5-dichloro-6-hydroxyindan-1,3-dione.

Step C: (1,3-Dioxo-2-ethyl-2phenyl-4,5-dichloro-6-indanyloxy)acetic acid

By the process of Example 7, Step G, but substituting for the 2-ethyl-2-methyl-4,5-dichloro-6-hydroxyindan-1,3-dione used therein, an equivalent amount of 2-ethyl-2-phenyl-4,5-dichloro-6-hydroxyindan-1,3-dione, there is obtained (1,3-dioxo-2-ethyl-2-phenyl-4,5-dichloro-6-indanyloxy)acetic acid.

EXAMPLE 9 5-[1',3'-Dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-yloxymethyl]tetrazole

Step A: 4'-Chloro-5'-methyl-6'-methoxyspiro(cyclopentane-1,2'-indan)-1',3'-dione

4'-Chloro-5'-methyl-6'-methoxyspiro(cyclopentane-1,2'-indan)-1',3'-dione is prepared following substantially the same procedure described in Example 1, Step A using the following substances:

    2-Methyl-3-chloroanisole                                                                           7.8 g.                                                                               (0.05 mole)                                          Cyclopentane-1,1-dicarbonyl chloride                                                               10.7 g.                                                                              (0.055 mole)                                         Methylene chloride  400 ml.                                                    Aluminum chloride   14.7 g.                                                                              (0.11 mole)                                     

The above procedure gives 11 g. of 4'-chloro-5'-methyl-6'-methoxyspiro(cyclopentane-1,2'-indan)-1',3'-dione which after recrystallization from ethanol-water melts at 156°-7°C.

Elemental analysis for C₁₅ H₁₅ Cl0₃ : Calc: C, 64.64; H, 5.42; Found: C, 65.12; H, 5.47.

Step B: 4'-Chloro-5'-methyl-6'-hydroxyspiro-(cyclopentane-1,2'-indan)-1',3'-dione

4'-Chloro-5'-methyl-6'-hydroxyspiro(cyclopentane-1,2'-indan)-1',3'-dione) is prepared following substantially the same procedure described in Example 1 Step B using the following substances:

    4'-Chloro-5'-methyl-6'-methoxyspiro-                                            (cyclopentane-1,2'-indan)-1,3'-dione                                                               10.5 g.                                                                              (0.0375 mole)                                       Pyridine hydrochloride                                                                              75 g.                                                

The above procedure gives 9.8 g. of 4'-chloro-5'-methyl-6'-hydroxyspiro(cyclopentane-1,2'-indan)-1',3'-dione which after recrystallization from acetic acid-water melts at 297°-8°C.

Elemental analysis for C₁₄ H₁₃ C10₃ : Calc.: C, 63.52; H, 4.95; Found: C, 63.47; H, 4.89.

Step C: [1',3'-Dioxo-4'-chloro-5'-methylspiro-(cyclopentane-1,2'-indan)-6'-yloxy acetonitrile

A stirred mixture of 4'-chloro-5'-methyl-6'-hydroxyspiro(cyclopentane-1,2'-indan)-1',3'-dione (9.3 g., 0.035 mole), chloroacetonitrile (2.83 g., 0.0375 mole), potassium carbonate (5.2 g., 0.0375 mole) and potassium iodide (6.2 g., 0.0375 mole) in dimethylformamide (100 ml.) is heated at 65°C. for 21/2 hours, cooled, then poured into water (1.5 1.) affording 10.7 g. of [1',3'-dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-yloxy]acetonitrile which melts at 137°-9°C. after recrystallization from ethanol-water.

Elemental analysis for C₁₆ H₁₄ ClNO₃ : Calc.: C, 63.27; H, 4.65; N, 4.61; Found: C, 63.54; H, 4.74; N, 4.63.

Step D: 5 -[1',3'-Dioxo-4'-chloro-5'-methylspiro-(cyclopentane-1,2'-indan)-6'-yloxymethyl]-tetrazole

A stirred mixture of [1',3'-dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-yloxy]acetonitrile (9.0 g., 0.03 mole), sodium azide (3.9 g., 0.06 mole) and ammonium chloride (3.2 g., 0.06 mole) in dimethylformamide (150 ml.) is heated at 95°C. for 2 hours then cooled and poured into dilute aqueous hydrochloric acid affording 9.9 g. of 5-[1',3'-dioxo-4'-chloro-5'-methylspiro(cyclopentane-1,2'-indan)-6'-yloxymethyl]tetrazole which melts at 211°-212°C. after recrystallization from acetic acid-water.

Elemental analysis for C₁₆ H₁₅ ClN₄ O₃ : Calc.: C, 55.42; H, 4.36; N, 16.16; Found: C, 55.38; H, 4.29; N, 16.37.

The novel compounds of this invention are diuretic and saluretic agents. In addition, these compounds are also able to maintain the uric acid concentration in the blood at pretreatment levels or even cause a decrease in uric acid concentration. The compounds of this invention can be administered to patients (both animal and human) in a wide variety of therapeutic dosages in conventional vehicles as, for example, by oral administration in the form of a tablet or by intravenous injection. Also, the daily dosage of the products may be varied over a wide range as, for example, in the form of scored tablets containing 5, 10, 25, 50, 100, 150, 250, 500 and 1000 milligrams of the active ingredient for the symptomatic adjustment of the dosage to the patient to be treated. These dosages are well below the toxic or lethal dose of the products.

A suitable unit dosage form of the products of this invention can be administered by mixing 50 milligrams of a [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy (or thio)]alkanoic acid (I) or a suitable salt, ester or amide derivative thereof, with 149. mg. of lactose and 1 mg. of magnesium stearate and placing the 200 mg. mixture into a No. 1 gelatin capsule. Similarly, by employing more of the active ingredient and less lactose, other dosage forms can be put up in No. 1 gelatin capsules and, should it be necessary to mix more than 200 mg. of ingredients together, larger capsules may be employed. Compressed tablets, pills, or other desired unit dosages can be prepared to incorporate the compounds of this invention by conventional methods, and if desired, can be made up as elixirs or as injectable solutions by methods well known to pharmacists. An effective amount of the drug is ordinarily supplied at a dosage level of from about 1 mg. to about 50 mg./kg. of body weight. Preferably the range is from about 1 mg. to 7 mg./kg. of body weight.

It is also within the scope of this invention to combine two or more of the compounds of this invention in a unit dosage form or to combine one or more of the compounds of this invention with other known diuretics and saluretics or with other desired therapeutic and/or nutritive agents in dosage unit form.

The following example is included to illustrate the preparation of a representative dosage form:Dry-filled capsules containing 50 mg. of active ingredientper capsule Per Capsule______________________________________(1,3-Dioxo-2,2-diethyl-4- chloro-5-methyl-6-indan- yloxy) acetic acid 50 mg.Lactose 149 mg.Magnesium Stearate 1 mg.Capsule (Size No. 1) 200 mg.______________________________________

The (1,3-dioxo-2,2-diethyl-4-chloro-5-methyl-6-indanyloxy)acetic acid is reduced to a No. 60 powder and then lactose and magnesium stearate are passed through a No. 60 bolting cloth onto the powder and the combined ingredients admixed for 10 minutes and then filled into a No. 1 dry gelatin capsule.

Similar dry-filled capsules can be prepared by replacing the active ingredient of the above example by any of the other novel compounds of this invention.

It will be apparent from the foregoing description that the [1,3-dioxo-2-substituted and 2,2-disubstituted-indanyloxy(or thio)alkanoic acid (I) of this invention constitute a valuable class of compounds which have not been prepared heretofore. One skilled in the art will also appreciate that the processes disclosed in the above examples are merely illustrative and are capable of a wide variation and modification without departing from the spirit of this invention. 

What is claimed is:
 1. A compound of the formula: ##SPC14##wherein R is lower alkyl having from 1 to 5 carbon atoms, cycloalkyl having 5 to 6 nuclear carbon atoms, phenyl or substituted phenyl wherein the substituent is lower alkyl or halo; R¹ is hydrogen, lower alkyl having 1 to 5 carbon atoms, lower alkenyl having 3 to 5 carbon atoms, lower alkynyl having from 3 to 5 carbon atoms, phenyl lower alkyl wherein lower alkyl has 1 to 3 carbon atoms or phenyl lower alkenyl or hydroxy lower alkyl; phenyl, or substituted phenyl wherein the substituent is lower alkyl or halo; or R and R¹ may be joined together with the carbon atom to which they are attached to form a cycloalkyl having from 3 to 7 nuclear carbon atoms; X¹ is hydrogen, methyl or halo and X² is methyl or halo; orY is alkylene or haloalkylene containing a maximum of 4 carbon atoms,and the non-toxic, pharmacologically acceptable salt and lower alkyl ester derivative thereof.
 2. A compound of the formula: ##SPC15##wherein R³ is lower alkyl having from 1 to 3 carbon atoms or cycloalkyl having from 5 to 6 nuclear carbon atoms; R⁴ is hydrogen, lower alkyl having from 1 to 3 carbon atoms or phenyl, or R³ and R⁴ may be joined together with the carbon atom to which they are attached to form a cycloalkyl radical containing from 5 to 6 nuclear carbon atoms; X³ and X⁴ are the same or different radicals selected from methyl or chloro, its racemic form, its enantiomers and its non-toxic, pharmaceutically acceptable salt, and lower alkyl ester derivative thereof.
 3. A compound of the formula: ##SPC16##wherein R⁷ is lower alkyl having 1 to 3 carbon atoms; R⁸ is lower alkyl having from 1 to 3 carbon atoms; X³ and X⁴ are the same or different radicals selected from methyl or chloro, its racemic form, its enantiomers and its non-toxic, pharmacologically acceptable salt and lower alkyl ester derivative thereof.
 4. A compound according to claim 2 wherein R³ and R⁴ are ethyl and X³ and X⁴ are methyl.
 5. A compound according to claim 2 wherein R³ is ethyl; R⁴ is methyl and X³ and X⁴ are chloro.
 6. A compound according to claim 2 wherein R³ and R⁴ are ethyl and X³ is methyl and X⁴ is chloro.
 7. A compound according to claim 2 wherein R³ is hydrogen, R⁴ is ethyl and X³ and X⁴ are methyl.
 8. A compound according to claim 2 wherein R³ and R⁴ are joined to form together with the carbon to which they are attached, a cyclopentyl radical and X³ is methyl and X⁴ is chloro.
 9. A compound according to claim 2 wherein R³ is methyl; R⁴ is cyclopentyl and X³ is methyl and X⁴ is chloro.
 10. A compound according to claim 2 wherein R³ is ethyl; R⁴ is phenyl and X³ and X⁴ are chloro. 